Characterization of candidate urine-based biomarkers of prostate cancer. A to C, qPCR was performed on WTA cDNA from urine obtained from patients presenting for needle biopsy or prostatectomy. Biomarker expression in patients with negative needle biopsies (green) or patients with prostate cancer (PCa; positive needle biopsy or prostatectomy; red) is shown. Normalization was performed using −ΔCt, with PCA3 normalized to urine PSA expression as performed previously (25). AMACR, ERG, GOLPH2, SPINK1, and TFF3 were normalized to the average of urine sediment PSA and GAPDH expression. TMPRSS2:ERG gene fusion expression was dichotomized as positive or negative. The −ΔCt values of genes that were not significant predictors of prostate cancer by univariate analysis (see Table 1) are shown in A, and the expression of those that were significant predictors is shown in B and C. P values from the univariate analysis for the detection of prostate cancer are indicated. D, ROC curves for individual variables for the diagnosis of prostate cancer. AUCs for GOLPH2, PCA3, SPINK1, and serum PSA are 0.664, 0.661, 0.642, and 0.508, respectively.